1. Technical Field
The present invention relates to a zoom lens for use in video cameras, digital still cameras and the like that are provided with a blurred image compensation function for optically compensating blurring of images caused by camera shake, vibration and the like, and also to an optical apparatus such like video camera and digital still camera using such the zoom lens.
2. Description of the Background Art
Recently, the anti-shaking function of preventing vibrations such as camera shake is becoming essential for image capturing systems such as video cameras, and various types of anti-shaking optical systems have been proposed.
For example, in the video camera disclosed in JP H8-029737A, an optical system for camera shake correction constituted by two lenses is mounted at the front of a zoom lens and one of the two lenses is moved perpendicularly to the optical axis so as to compensate for fluctuation of the image caused by camera shake.
Also, in the video camera disclosed in JP H7-128619A, a four-group zoom lens is used and a portion of the third lens group constituted by a plurality of lenses is moved perpendicularly to the optical axis so as to compensate for fluctuation of the image caused by camera shake.
However, in the video camera disclosed in JP H8-029737A described above, the lens diameter of the optical system for camera shake correction is increased since the optical system for camera shake correction is mounted at the front of the zoom lens. The size of the video camera itself and the load on the actuating system are increased correspondingly, so that the system is unfavorable in order to reduce the size, weight and energy consumption.
In the video camera disclosed in JP H7-128619A above, since a part of the third lens group which is fixed with respect to the image plane is moved perpendicular to the optical axis so as to correct fluctuation of the image, this type of system is more favorable in terms of the size compared to the type in which the optical system for camera shake correction is mounted at the front of the zoom lens. However, the deterioration in chromatic aberration during camera shake correction is unavoidable because a part of the third lens group is moved.